Attention is directed to U.S. Pat. No. 5,1487,707 (D/94226), entitled, xe2x80x9cPuzzle Cut Seamed Belt with Bonding Between Adjacent Surfaces by UV Cured Adhesive;xe2x80x9d U.S. Pat. No. 5,514,436 (D/94226), entitled, xe2x80x9cEndless Puzzle Cut Seamed Belt;xe2x80x9d U.S. patent application Ser. No. 08/297,203 (D/94227), entitled xe2x80x9cPuzzle Cut Seamed Belt with Bonding Between Adjacent Surfaces:xe2x80x9d U.S. patent application Ser. No. 08/522,622 (D/93563) entitled xe2x80x9cPuzzle Cut Seamed Belt with Strength Enhancing Strip,xe2x80x9d now continuing U.S. patent application Ser. No. 08/522,622 (D/935630C), filed Aug. 31, 1995; U.S. patent application Ser. No. 08/004,636 (D/97525) entitled xe2x80x9cProcess and Apparatus for Producing an Endless Seamed Belt;xe2x80x9d U.S. patent application Ser. No. 09/493,445 (D/97525D), filed Jan. 28, 2000, entitled xe2x80x9cProcess and Apparatus for Producing an Endless Seamed Belt;xe2x80x9d U.S. patent application Ser. No. 09/470,931 (D/99698), tiled Dec. 22, 1999, entitled, xe2x80x9cContinuous Process for Manufacturing Imagable Seamed Belts for Printers;xe2x80x9d U.S patent application Ser. No. 09/615,426, (D/99598), filed Jul. 13, 2000, entitled, xe2x80x9cPolyimide Adhesive For Polyimide Component Interlocking Seams;xe2x80x9d and U.S. patent application Ser. No. 09/088,011, (D/97683), filed May 28, 1998, entitled, xe2x80x9cUnsaturated Carbonate Adhesives for Component Seams.xe2x80x9d The disclosures of each of these references are hereby incorporated by reference in their entirety.
The present invention is directed to a process for seaming interlocking seams of an endless flexible seamed component, in order to provide a belt, film or sheet component wherein an image can be transferred at the seam of the component with little or no print defects caused by the seam. In embodiments, the present invention relates to processes for producing xerographic component imagable polyimide seamed belts comprising an adhesive formed between mutually mating elements of a seam, wherein the adhesive comprises a polyimide material. The present invention, in embodiments, provides a component in which the seam has compatible electrical and release properties with the rest of the component. The present invention further provides, in embodiments, a component having a seam with increased strength. The present invention, in embodiments, also provides a component having a seam in which the height differential between the seam and the rest of the component is virtually nil. The component, in embodiments, allows for image transfer at the seam, which cannot be accomplished with known seamed components.
In a typical electrostatographic reproducing apparatus such as an electrophotographic imaging system using a photosensitive member, a light image of an original to be copied is recorded in the form of an electrostatic latent image upon a photosensitive member and the latent image is subsequently rendered visible by the application of a developer mixture. One type of developer used in such printing machines is a liquid developer comprising a liquid carrier having toner particles dispersed therein. Generally, the toner is made up of resin and a suitable colorant such as a dye or pigment. Conventional charge director compounds may also be present. The liquid developer material is brought into contact with the electrostatic latent image and the colored toner particles are deposited thereon in image configuration.
The developed toner image recorded on the imaging member is transferred to an image receiving substrate such as paper via a transfer member. The toner particles may be transferred by heat and/or pressure to a transfer member, or more commonly, the toner image particles may be electrostatically transferred to the transfer member by means of an electrical potential between the imaging member and the transfer member. After the toner has been transferred to the transfer member, it is then transferred to the image receiving substrate, for example by contacting the substrate with the toner image on the transfer member under heat and/or pressure.
Transfer members enable high throughput at modest process speeds. In four-color photocopier or printer systems, the transfer member also improves registration of the final color toner image. In such systems, the four component colors of cyan, yellow, magenta and black may be synchronously developed onto one or more imaging members and transferred in registration onto a transfer member at a transfer station.
In electrostatographic printing and photocopy machines in which the toner image is transferred from the transfer member to the image receiving substrate, it is desired that the transfer of the toner particles from the transfer member to the image receiving substrate be substantially 100 percent. Less than complete transfer to the image receiving substrate results in image degradation and low resolution. Complete transfer is particularly desirable when the imaging process involves generating full color images since undesirable color deterioration in the final colors can occur when the color images are not completely transferred from the transfer member.
Thus, it is desirable that the transfer member surface has excellent release characteristics with respect to the toner particles. Conventional materials known in the art for use as transfer members often possess the strength, conformability and electrical conductivity necessary for use as transfer members, but can suffer from poor toner release characteristics, especially with respect to higher gloss image receiving substrates.
Polyimide substrate transfer members are suitable for high performance applications because of their outstanding mechanical strength and thermal stability, in addition to their good resistance to a wide range of chemicals. However, the high cost of manufacturing unseamed polyimide transfer members has led to the introduction of a seamed belt. Belt, as used herein, will refer to belts, films, sheets and the like members. Even polyimides with the best mechanical and chemical properties often exhibit poor adhesion at the seam even when commercially available primers are used.
In the electrostatic transfer applications, use of a seamed transfer polyimide member results in insufficient transfer in that the developed image occurring on the seam is not adequately transferred. This incomplete transfer is partially the result of the difference in seam height to the rest of the belt. A xe2x80x9cbumpxe2x80x9d is formed at the seam, thereby hindering transfer and mechanical performance. The development of puzzle cut seams has increased the quality of transfer somewhat, by decreasing the seam height, thereby allowing smooth cycling. However, even with the improvements made with puzzle cut seams, quality imaging in the seamed area has not been obtainable due to contrast in transfer caused by differences in electrical and release properties of known seaming adhesives. Further, current adhesives do not provide sufficient bonding strength at the seam, resulting in short belt life.
Currently, puzzle cut seam adhesives consist of uv-curable epoxies and hot-melt adhesives. While these adhesives exhibit acceptable strengths at room temperature under tensile load, most undergo premature failure at elevated temperatures. Additionally, the existing adhesives have been found to perform poorly under some important dynamic test conditions.
Therefore, it is desired to provide a more robust adhesive system useful to seam puzzle cut seamed polyimide belts. It is further desirable to provide an adhesive system that allows the seam to have thermal and mechanical characteristics closely matching those of the robust polyimide substrate. Further, it is desired to provide an adhesive having electrical, mechanical and toner release characteristics that closely match those of the substrates. In addition, it is desirable to provide a seam that is imagable, thereby reducing or eliminating the presence of print or copy defects.
U.S. Pat. No. 5,549,193 relates to an endless flexible seamed belt comprising puzzle cut members, wherein at least one receptacle has a substantial depth in a portion of the belt material at the belt ends.
Embodiments of the present invention include: a process for producing an imagable seam in a polyimide component, wherein the component comprises a seam having a first end and a second end, each of the first end and the second end comprising a plurality of mutually mating elements which join in an interlocking relationship to form a seam, the belt comprising a polyimide substrate, the process comprising: a) providing a poly(amic acid) material between said mutually mating elements; and b) curing said poly(amic acid) material while present between said mutually mating elements to form a polyimide seam.
In addition, embodiments of the present invention include: a process for producing an imagable seam in a polyimide component, wherein the component comprises a seam having a first end and a second end, each of the first end and the second end comprising a plurality of mutually mating elements which join in an interlocking relationship to form a seam, the belt comprising a polyimide substrate, the process comprising: a) treating the mutually mating elements with a basic material; b) treating the mutually mating elements with an acid material; c) providing a poly(amic acid) material between the mutually mating elements; and d) curing the poly(amic acid) material while present between the mutually mating elements to form a polyimide seam.
Embodiments further include: a process for producing an imagable seam in a polyimide component, wherein the component comprises a seam having a first end and a second end, each of the first end and the second end comprising a plurality of mutually mating elements which join in an interlocking relationship to form a seam, the belt comprising a polyimide substrate, the process comprising: a) treating the mutually mating elements with a basic material; b) rinsing the mutually mating elements; c) treating the mutually mating elements with an acid material; d) rinsing the mutually mating elements; e) providing a poly(amic acid) material between the mutually mating elements; and f) curing the poly(amic acid) material while present between the mutually mating elements to form a polyimide seam.